Habitech Systems Unavoidably Energy Efficient Homes

Habitech Systems’ Managing Director, Chris Barnett, points to a chart of air leakage test results for a range of houses. It shows that a house designed to an 8 star energy rating standard can actually perform as poorly as an old, unrated house. “It’s the equivalent of heating a home while leaving a one and a half square metre window wide open,” he says.

Why don’t these houses perform as intended? It’s largely it’s due to a lack of oversight and enforcement of the standards and corner cutting during construction, as highlighted in the National Energy Efficient Building Program commissioned by the Federal Governments.

Chris set out to develop a solution, and came up with a construction system in which compliance is an integral part of how the building is constructed.

Take a SIP

Habitech Systems grew out of a research project undertaken by Chris’s architectural firm, Third Skin Sustainability. The aim was to create a system that ensures the delivered homes are as energy efficient as they are designed to be. As it turns out, many Habitech Systems homes actually perform better than expected.

Habitech creates buildings with a range of smart manufactured components. They use long span, insulated roof panels and construct walls with a structural insulated panel (SIP) system they have developed and manufacture in Melbourne. SIPs can be made in different ways, but in Habitech’s case they comprise a core of highly-insulating expanded polystyrene foam (EPS) bonded to an inner layer of local, plantation-grown radiata pine plywood, and an outer skin made from magnesium oxide, wood pulp and fibreglass.

SIPs make for a simple, well insulated building system.

Flat-packed houses

Factory conditions and the rigidity of the panel’s components allow panels to be made with minimum waste and millimetre precision. There’s no fluffy insulation to sag or be skipped, and panel numbering along with detailed assembly instructions ensure each panel ends up exactly where it should. With the right windows and doors the result is a home that is so airtight it either needs natural background ventilation added in the form of louver windows (which have a degree of air-leakage), or the addition of ventilation system with an inbuilt heat exchanger. This latter option provides the best energy performance and guarantees healthy internal fresh air circulation.

Panels are shipped flat-packed on trucks and can easily be carried onto sites that are difficult to access. Construction is quick. For a typical Habitech house it takes about two to three weeks to go from concrete slab to lock-up.

A mix of ingredients

Achieving the end result is about more than just a SIPs wall system. Site selection, a design that soaks up winter sun, double-glazing and thermal mass in the form of an insulated concrete slab also play a part. However, the magic ingredient is attitude. It begins with clients who share Chris’s passion for more sustainable homes, and extends to the choice of builders who also ‘get it’. “This,” Chris says, “allows us to provide a turn-key service that’s all about delivered performance”.

‘Designing in’ good performance also means creating homes that are the right size and without wasted space.

It also means working with clients who want clean energy. Most opt for a three or four kilowatt solar power system, which is large enough to achieve energy neutrality across the year. And with the future in mind, Chris recommends installing a hybrid power inverter, to allow for the future addition of battery storage.

Habitech's Nimbus house is a more economical option for some home buyers.

More sustainable, more resilient

At present Chris describes Habitech’s system as “more sustainable”, with the goal to be truly sustainable. While all the components of the SIPs are recyclable, one challenge is to find an alternative to the current EPS, ideally something from a renewable source that is also, ultimately, biodegradable.

Habitech homes nicely illustrate that the tools of sustainability are often the same as the tools of resilience. SIPs create stronger buildings – 800% stronger than a standard stud frame – so can cope with higher winds. They provide their occupants with better protection from extreme heat as well as the cold. Combine these features with a suitable building site and the result is a home that can stand up to a future of more frequent and intense major weather events. ­­

Comfort and cost

For many people the attraction of a Habitech home is the greater comfort that results from reduced temperature fluctuations. Lower running costs are also a big drawcard, and with frequent air changes via an energy-efficient heat exchanger, the homes are also healthier.

While all projects to date have been custom designed, Habitech Systems has created its Nimbus house, a standard design suited to a typical building block. The core is a two bedroom, one bathroom home with the option to add on additional rooms, either initially or in the future. A standard design, combined with the automation of panel production that higher volumes will allow, will help to reduce costs.

More Habitech

“With more awareness of the total cost of owning a home, including heating and cooling, more people are showing an interest in what we do,” Chris says. Interstate expansion is happening now, with a project in Tasmania underway, another on the drawing board for South Australia, and plans for design offices in other states, too.

It’s tempting to sum up Habitech Systems as creating homes for our times. But with their inherent strength, comfort and low energy requirements, they are also very much homes for our future.